In waste such as waste electronic components or waste electronic substrates (combustible scrap, referred to as combustible materials below), valuable metals such as copper (Cu), gold (Au), silver (Ag), platinum (Pt), and palladium (Pd) are contained together with combustible plastics.
While such combustible materials are used for heating molten substance by charging (feeding) the combustible materials into a smelting furnace such as a continuous copper-smelting installation and burning and melting (the term of “burning and melting” used in the specification refers to “burning and/or melting”) the combustible materials, the valuable metals are recovered with copper in the post-process.
In the related art, for example, as disclosed in PTLs 1 and 2 below, combustible material containing valuable metals is allowed to fall onto a molten substance surface of molten substance from a charging port provided on a ceiling wall or a side wall of a furnace body. In addition, in PTLs 1 and 2, the combustible material is press-formed into a lump and charged into the molten substance and thus a waste heat boiler or the like is prevented from being damaged. That is, for example, when the combustible material is allowed to fall into the molten substance in a state in which the combustible material is finely crushed into powder or particles instead of press-forming the combustible material into a lump, the combustible material is easily discharged together with a flue gas from a gas zone (a space above the molten substance surface) of the furnace body and burned in the waste heat boiler. Thus, there is a concern of damaging the waste heat boiler or the like.
In addition, a lance pipe which is opened to the molten substance surface is provided above the molten substance surface of the molten substance in the furnace body. Mineral ores (concentrates) containing nonferrous metals such as copper ores and oxygen-enriched air (air having an oxygen content of about 40% to 70%) are blown onto the molten substance surface of the molten substance from the lance pipe. Further, in order to maintain the temperature of the molten substance within a predetermined high temperature range, coke or powdered coal (hereinafter, collectively referred to as “coal”) is charged as a fuel for heat compensation.